struct dentry *wrapfs_lookup(struct inode *dir, struct dentry *dentry,
			     struct nameidata *nd)
{
	struct dentry *ret, *parent;
	struct path lower_parent_path;
	int err = 0;

	BUG_ON(!nd);
	parent = dget_parent(dentry);

	wrapfs_get_lower_path(parent, &lower_parent_path);

	/* allocate dentry private data.  We free it in ->d_release */
	err = new_dentry_private_data(dentry);
	if (err) {
		ret = ERR_PTR(err);
		goto out;
	}
	ret = __wrapfs_lookup(dentry, nd->flags, &lower_parent_path);
	if (IS_ERR(ret))
		goto out;
	if (ret)
		dentry = ret;
	if (dentry->d_inode)
		fsstack_copy_attr_times(dentry->d_inode,
					wrapfs_lower_inode(dentry->d_inode));
	/* update parent directory's atime */
	fsstack_copy_attr_atime(parent->d_inode,
				wrapfs_lower_inode(parent->d_inode));

out:
	wrapfs_put_lower_path(parent, &lower_parent_path);
	dput(parent);
	return ret;
}
/*
 * On success:
 *	fills dentry object appropriate values and returns NULL.
 * On fail (== error)
 *	returns error ptr
 *
 * @dir : Parent inode. It is locked (dir->i_mutex)
 * @dentry : Target dentry to lookup. we should set each of fields.
 *	     (dentry->d_name is initialized already)
 * @nd : nameidata of parent inode
 */
struct dentry *sdcardfs_lookup(struct inode *dir, struct dentry *dentry,
		unsigned int flags)

{
	struct dentry *ret = NULL, *parent;
	struct path lower_parent_path;
	int err = 0;
	struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
	const struct cred *saved_cred = NULL;

	parent = dget_parent(dentry);

	if(!check_caller_access_to_name(parent->d_inode, dentry->d_name.name,
						sbi->options.derive, 0, 0)) {
		ret = ERR_PTR(-EACCES);
		printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
                         "	dentry: %s, task:%s\n",
						 __func__, dentry->d_name.name, current->comm);
		goto out_err;
        }

	/* save current_cred and override it */
	OVERRIDE_CRED_PTR(SDCARDFS_SB(dir->i_sb), saved_cred);

	sdcardfs_get_lower_path(parent, &lower_parent_path);

	/* allocate dentry private data.  We free it in ->d_release */
	err = new_dentry_private_data(dentry);
	if (err) {
		ret = ERR_PTR(err);
		goto out;
	}

	ret = __sdcardfs_lookup(dentry, flags, &lower_parent_path);
	if (IS_ERR(ret))
	{
		goto out;
	}
	if (ret)
		dentry = ret;
	if (dentry->d_inode) {
		fsstack_copy_attr_times(dentry->d_inode,
					sdcardfs_lower_inode(dentry->d_inode));
		/* get drived permission */
		get_derived_permission(parent, dentry);
		fix_derived_permission(dentry->d_inode);
	}
	/* update parent directory's atime */
	fsstack_copy_attr_atime(parent->d_inode,
				sdcardfs_lower_inode(parent->d_inode));

out:
	sdcardfs_put_lower_path(parent, &lower_parent_path);
	REVERT_CRED(saved_cred);
out_err:
	dput(parent);
	return ret;
}
Example #3
0
/*
 * unionfs_lookup is the only special function which takes a dentry, yet we
 * do NOT want to call __unionfs_d_revalidate_chain because by definition,
 * we don't have a valid dentry here yet.
 */
static struct dentry *unionfs_lookup(struct inode *dir,
				     struct dentry *dentry,
				     /* XXX: pass flags to lower? */
				     unsigned int flags_unused)
{
	struct dentry *ret, *parent;
	int err = 0;

	unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
	parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);

	/*
	 * As long as we lock/dget the parent, then can skip validating the
	 * parent now; we may have to rebuild this dentry on the next
	 * ->d_revalidate, however.
	 */

	/* allocate dentry private data.  We free it in ->d_release */
	err = new_dentry_private_data(dentry, UNIONFS_DMUTEX_CHILD);
	if (unlikely(err)) {
		ret = ERR_PTR(err);
		goto out;
	}

	ret = unionfs_lookup_full(dentry, parent, INTERPOSE_LOOKUP);

	if (!IS_ERR(ret)) {
		if (ret)
			dentry = ret;
		/* lookup_full can return multiple positive dentries */
		if (dentry->d_inode && !S_ISDIR(dentry->d_inode->i_mode)) {
			BUG_ON(dbstart(dentry) < 0);
			unionfs_postcopyup_release(dentry);
		}
		unionfs_copy_attr_times(dentry->d_inode);
	}

	unionfs_check_inode(dir);
	if (!IS_ERR(ret))
		unionfs_check_dentry(dentry);
	unionfs_check_dentry(parent);
	unionfs_unlock_dentry(dentry); /* locked in new_dentry_private data */

out:
	unionfs_unlock_parent(dentry, parent);
	unionfs_read_unlock(dentry->d_sb);

	return ret;
}
Example #4
0
/* 
 * On success:
 * 	fills dentry object appropriate values and returns NULL. 
 * On fail (== error)
 * 	returns error ptr
 *
 * @dir : Parent inode. It is locked (dir->i_mutex)
 * @dentry : Target dentry to lookup. we should set each of fields.
 *	     (dentry->d_name is initialized already)
 * @nd : nameidata of parent inode 
 */
struct dentry *sdcardfs_lookup(struct inode *dir, struct dentry *dentry,
			     struct nameidata *nd)
{
	struct dentry *ret, *parent;
	struct path lower_parent_path;
	int err = 0;

	OVERRIDE_CRED_PTR(SDCARDFS_SB(dir->i_sb));

	parent = dget_parent(dentry);

	sdcardfs_get_lower_path(parent, &lower_parent_path);

	/* allocate dentry private data.  We free it in ->d_release */
	err = new_dentry_private_data(dentry);
	if (err) {
		ret = ERR_PTR(err);
		goto out;
	}

	ret = __sdcardfs_lookup(dentry, nd, &lower_parent_path);
	if (IS_ERR(ret))
	{
		goto out;
	}
	if (ret) 
		dentry = ret;
	if (dentry->d_inode)
		fsstack_copy_attr_times(dentry->d_inode,
					sdcardfs_lower_inode(dentry->d_inode));
	/* update parent directory's atime */
	fsstack_copy_attr_atime(parent->d_inode,
				sdcardfs_lower_inode(parent->d_inode));

out:
	sdcardfs_put_lower_path(parent, &lower_parent_path);
	dput(parent);
	REVERT_CRED();
	return ret;
}
struct dentry *amfs_lookup(struct inode *dir, struct dentry *dentry,
			     unsigned int flags)
{
	int err;
	struct dentry *ret, *parent;
	struct path lower_parent_path;

	parent = dget_parent(dentry);

	amfs_get_lower_path(parent, &lower_parent_path);

	/* allocate dentry private data.  We free it in ->d_release */
	err = new_dentry_private_data(dentry);
//	 printk("\n lookup.c-> dentry *amfs_lookup"); //aditi

	if (err) {
		ret = ERR_PTR(err);
		goto out;
	}
	ret = __amfs_lookup(dentry, flags, &lower_parent_path);
	if (IS_ERR(ret))
		goto out;
	if (ret)
		dentry = ret;
	if (dentry->d_inode)
		fsstack_copy_attr_times(dentry->d_inode,
					amfs_lower_inode(dentry->d_inode));
	/* update parent directory's atime */
	fsstack_copy_attr_atime(parent->d_inode,
				amfs_lower_inode(parent->d_inode));

out:
	amfs_put_lower_path(parent, &lower_parent_path);
	dput(parent);
	return ret;
}
Example #6
0
/*
 * our custom d_alloc_root work-alike
 *
 * we can't use d_alloc_root if we want to use our own interpose function
 * unchanged, so we simply call our own "fake" d_alloc_root
 */
static struct dentry *sdcardfs_d_alloc_root(struct super_block *sb)
{
	struct dentry *ret = NULL;

	if (sb) {
		static const struct qstr name = {
			.name = "/",
			.len = 1
		};

		ret = __d_alloc(sb, &name);
		if (ret) {
			d_set_d_op(ret, &sdcardfs_ci_dops);
			ret->d_parent = ret;
		}
	}
	return ret;
}

/*
 * There is no need to lock the sdcardfs_super_info's rwsem as there is no
 * way anyone can have a reference to the superblock at this point in time.
 */
static int sdcardfs_read_super(struct super_block *sb, const char *dev_name, 
						void *raw_data, int silent)
{
	int err = 0;
	int debug;
	struct super_block *lower_sb;
	struct path lower_path;
	struct sdcardfs_sb_info *sb_info;
	void *pkgl_id;

	printk(KERN_INFO "sdcardfs: version %s\n", SDCARDFS_VERSION);

	if (!dev_name) {
		printk(KERN_ERR
		       "sdcardfs: read_super: missing dev_name argument\n");
		err = -EINVAL;
		goto out;
	}

	printk(KERN_INFO "sdcardfs: dev_name -> %s\n", dev_name);
	printk(KERN_INFO "sdcardfs: options -> %s\n", (char *)raw_data);

	/* parse lower path */
	err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
			&lower_path);
	if (err) {
		printk(KERN_ERR	"sdcardfs: error accessing "
		       "lower directory '%s'\n", dev_name);
		goto out;
	}

	/* allocate superblock private data */
	sb->s_fs_info = kzalloc(sizeof(struct sdcardfs_sb_info), GFP_KERNEL);
	if (!SDCARDFS_SB(sb)) {
		printk(KERN_CRIT "sdcardfs: read_super: out of memory\n");
		err = -ENOMEM;
		goto out_free;
	}

	sb_info = sb->s_fs_info;

	/* parse options */
	err = parse_options(sb, raw_data, silent, &debug, &sb_info->options);
	if (err) {
		printk(KERN_ERR	"sdcardfs: invalid options or out of memory\n");
		goto out_freesbi;
	}

	pkgl_id = packagelist_create();
	if(IS_ERR(pkgl_id))
		goto out_freesbi;
	else
		sb_info->pkgl_id = pkgl_id;

	/* set the lower superblock field of upper superblock */
	lower_sb = lower_path.dentry->d_sb;
	atomic_inc(&lower_sb->s_active);
	sdcardfs_set_lower_super(sb, lower_sb);

	/* inherit maxbytes from lower file system */
	sb->s_maxbytes = lower_sb->s_maxbytes;

	/*
	 * Our c/m/atime granularity is 1 ns because we may stack on file
	 * systems whose granularity is as good.
	 */
	sb->s_time_gran = 1;

	sb->s_magic = SDCARDFS_SUPER_MAGIC;
	if (sb_info->options.type != TYPE_NONE)
		sb->s_op = &sdcardfs_multimount_sops;
	else
		sb->s_op = &sdcardfs_sops;

	/* see comment next to the definition of sdcardfs_d_alloc_root */
	sb->s_root = sdcardfs_d_alloc_root(sb);
	if (!sb->s_root) {
		err = -ENOMEM;
		goto out_sput;
	}

	/* link the upper and lower dentries */
	sb->s_root->d_fsdata = NULL;
	err = new_dentry_private_data(sb->s_root);
	if (err)
		goto out_freeroot;

	/* set the lower dentries for s_root */
	sdcardfs_set_lower_path(sb->s_root, &lower_path);

	/* call interpose to create the upper level inode */
	err = sdcardfs_interpose(sb->s_root, sb, &lower_path);
	if (!err) {
		/* setup permission policy */
		if(sb_info->options.multi_user){
			setup_derived_state(sb->s_root->d_inode, 
				PERM_PRE_ROOT, sb_info->options.userid, AID_ROOT, sb_info->options.gid, false);
			sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL);
			snprintf(sb_info->obbpath_s, PATH_MAX, "%s/obb", dev_name);
			err =  prepare_dir(sb_info->obbpath_s, 
						sb_info->options.fs_low_uid,
						sb_info->options.fs_low_gid, 00775);
		} else {
			setup_derived_state(sb->s_root->d_inode,
				PERM_ROOT, sb_info->options.userid, AID_ROOT, sb_info->options.gid, false);
			sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL);
			snprintf(sb_info->obbpath_s, PATH_MAX, "%s/Android/obb", dev_name);
		}
		fix_derived_permission(sb->s_root->d_inode);

		sb_info->devpath = kzalloc(PATH_MAX, GFP_KERNEL);
		if(sb_info->devpath && dev_name)
			strncpy(sb_info->devpath, dev_name, strlen(dev_name));
		
		if (!silent && !err)
			printk(KERN_INFO "sdcardfs: mounted on top of %s type %s\n",
						dev_name, lower_sb->s_type->name);
		goto out;
	}
	/* else error: fall through */

	free_dentry_private_data(sb->s_root);
out_freeroot:
	dput(sb->s_root);
out_sput:
	/* drop refs we took earlier */
	atomic_dec(&lower_sb->s_active);
	packagelist_destroy(sb_info->pkgl_id);
out_freesbi:
	kfree(SDCARDFS_SB(sb));
	sb->s_fs_info = NULL;
out_free:
	path_put(&lower_path);

out:
	return err;
}
Example #7
0
/*
 * There is no need to lock the wrapfs_super_info's rwsem as there is no
 * way anyone can have a reference to the superblock at this point in time.
 */
static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent)
{
	int err = 0;
	struct super_block *lower_sb;
	struct path lower_path;
	char *dev_name = (char *) raw_data;
	struct inode *inode;

	if (!dev_name) {
		printk(KERN_ERR
		       "wrapfs: read_super: missing dev_name argument\n");
		err = -EINVAL;
		goto out;
	}

	/* parse lower path */
	err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
			&lower_path);
	if (err) {
		printk(KERN_ERR	"wrapfs: error accessing "
		       "lower directory '%s'\n", dev_name);
		goto out;
	}

	/* allocate superblock private data */
	sb->s_fs_info = kzalloc(sizeof(struct wrapfs_sb_info), GFP_KERNEL);
	if (!WRAPFS_SB(sb)) {
		printk(KERN_CRIT "wrapfs: read_super: out of memory\n");
		err = -ENOMEM;
		goto out_free;
	}

	/* set the lower superblock field of upper superblock */
	lower_sb = lower_path.dentry->d_sb;
	atomic_inc(&lower_sb->s_active);
	wrapfs_set_lower_super(sb, lower_sb);

	/* inherit maxbytes from lower file system */
	sb->s_maxbytes = lower_sb->s_maxbytes;

	/*
	 * Our c/m/atime granularity is 1 ns because we may stack on file
	 * systems whose granularity is as good.
	 */
	sb->s_time_gran = 1;

	sb->s_op = &wrapfs_sops;

	/* get a new inode and allocate our root dentry */
	inode = wrapfs_iget(sb, lower_path.dentry->d_inode);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_sput;
	}
	sb->s_root = d_alloc_root(inode);
	if (!sb->s_root) {
		err = -ENOMEM;
		goto out_iput;
	}
	d_set_d_op(sb->s_root, &wrapfs_dops);

	/* link the upper and lower dentries */
	sb->s_root->d_fsdata = NULL;
	err = new_dentry_private_data(sb->s_root);
	if (err)
		goto out_freeroot;

	/* if get here: cannot have error */

	/* set the lower dentries for s_root */
	wrapfs_set_lower_path(sb->s_root, &lower_path);

	/*
	 * No need to call interpose because we already have a positive
	 * dentry, which was instantiated by d_alloc_root.  Just need to
	 * d_rehash it.
	 */
	d_rehash(sb->s_root);
	if (!silent)
		printk(KERN_INFO
		       "wrapfs: mounted on top of %s type %s\n",
		       dev_name, lower_sb->s_type->name);
	goto out; /* all is well */

	/* no longer needed: free_dentry_private_data(sb->s_root); */
out_freeroot:
	dput(sb->s_root);
out_iput:
	iput(inode);
out_sput:
	/* drop refs we took earlier */
	atomic_dec(&lower_sb->s_active);
	kfree(WRAPFS_SB(sb));
	sb->s_fs_info = NULL;
out_free:
	path_put(&lower_path);

out:
	return err;
}
Example #8
0
struct dentry *unionfs_lookup_backend(struct dentry *dentry, struct nameidata *nd,
				      int lookupmode)
{
	int err = 0;
	struct dentry *hidden_dentry = NULL;
	struct dentry *wh_hidden_dentry = NULL;
	struct dentry *hidden_dir_dentry = NULL;
	struct dentry *parent_dentry = NULL;
	int bindex, bstart, bend, bopaque;
	int dentry_count = 0;	/* Number of positive dentries. */
	int first_dentry_offset = -1;
	struct dentry *first_hidden_dentry = NULL;
	struct vfsmount *first_hidden_mnt = NULL;
	int locked_parent = 0;
	int locked_child = 0;

	int opaque;
	char *whname = NULL;
	const char *name;
	int namelen;

	/* We should already have a lock on this dentry in the case of a
	 * partial lookup, or a revalidation. Otherwise it is returned from
	 * new_dentry_private_data already locked.
	 */
	if (lookupmode == INTERPOSE_PARTIAL || lookupmode == INTERPOSE_REVAL ||
	    lookupmode == INTERPOSE_REVAL_NEG)
		verify_locked(dentry);
	else {
		BUG_ON(UNIONFS_D(dentry) != NULL);
		locked_child = 1;
	}
	if (lookupmode != INTERPOSE_PARTIAL)
		if ((err = new_dentry_private_data(dentry)))
			goto out;
	/* must initialize dentry operations */
	dentry->d_op = &unionfs_dops;

	parent_dentry = dget_parent(dentry);
	/* We never partial lookup the root directory. */
	if (parent_dentry != dentry) {
		unionfs_lock_dentry(parent_dentry);
		locked_parent = 1;
	} else {
		dput(parent_dentry);
		parent_dentry = NULL;
		goto out;
	}

	name = dentry->d_name.name;
	namelen = dentry->d_name.len;

	/* No dentries should get created for possible whiteout names. */
	if (!is_validname(name)) {
		err = -EPERM;
		goto out_free;
	}

	/* Now start the actual lookup procedure. */
	bstart = dbstart(parent_dentry);
	bend = dbend(parent_dentry);
	bopaque = dbopaque(parent_dentry);
	BUG_ON(bstart < 0);

	/* It would be ideal if we could convert partial lookups to only have
	 * to do this work when they really need to.  It could probably improve
	 * performance quite a bit, and maybe simplify the rest of the code.
	 */
	if (lookupmode == INTERPOSE_PARTIAL) {
		bstart++;
		if ((bopaque != -1) && (bopaque < bend))
			bend = bopaque;
	}

	for (bindex = bstart; bindex <= bend; bindex++) {
		hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex);
		if (lookupmode == INTERPOSE_PARTIAL && hidden_dentry)
			continue;
		BUG_ON(hidden_dentry != NULL);

		hidden_dir_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex);

		/* if the parent hidden dentry does not exist skip this */
		if (!(hidden_dir_dentry && hidden_dir_dentry->d_inode))
			continue;

		/* also skip it if the parent isn't a directory. */
		if (!S_ISDIR(hidden_dir_dentry->d_inode->i_mode))
			continue;

		/* Reuse the whiteout name because its value doesn't change. */
		if (!whname) {
			whname = alloc_whname(name, namelen);
			if (IS_ERR(whname)) {
				err = PTR_ERR(whname);
				goto out_free;
			}
		}

		/* check if whiteout exists in this branch: lookup .wh.foo */
		wh_hidden_dentry = lookup_one_len(whname, hidden_dir_dentry,
						  namelen + UNIONFS_WHLEN);
		if (IS_ERR(wh_hidden_dentry)) {
			dput(first_hidden_dentry);
			mntput(first_hidden_mnt);
			err = PTR_ERR(wh_hidden_dentry);
			goto out_free;
		}

		if (wh_hidden_dentry->d_inode) {
			/* We found a whiteout so lets give up. */
			if (S_ISREG(wh_hidden_dentry->d_inode->i_mode)) {
				set_dbend(dentry, bindex);
				set_dbopaque(dentry, bindex);
				dput(wh_hidden_dentry);
				break;
			}
			err = -EIO;
			printk(KERN_NOTICE "EIO: Invalid whiteout entry type"
			       " %d.\n", wh_hidden_dentry->d_inode->i_mode);
			dput(wh_hidden_dentry);
			dput(first_hidden_dentry);
			mntput(first_hidden_mnt);
			goto out_free;
		}

		dput(wh_hidden_dentry);
		wh_hidden_dentry = NULL;

		/* Now do regular lookup; lookup foo */
		nd->dentry = unionfs_lower_dentry_idx(dentry, bindex);
		/* FIXME: fix following line for mount point crossing */
		nd->mnt = unionfs_lower_mnt_idx(parent_dentry, bindex);

		hidden_dentry = lookup_one_len_nd(name, hidden_dir_dentry,
					       namelen, nd);
		if (IS_ERR(hidden_dentry)) {
			dput(first_hidden_dentry);
			mntput(first_hidden_mnt);
			err = PTR_ERR(hidden_dentry);
			goto out_free;
		}

		/* Store the first negative dentry specially, because if they
		 * are all negative we need this for future creates.
		 */
		if (!hidden_dentry->d_inode) {
			if (!first_hidden_dentry && (dbstart(dentry) == -1)) {
				first_hidden_dentry = hidden_dentry;
				/* FIXME: following line needs to be changed
				 * to allow mountpoint crossing
				 */
				first_hidden_mnt = mntget(
					unionfs_lower_mnt_idx(parent_dentry,
								bindex));
				first_dentry_offset = bindex;
			} else
				dput(hidden_dentry);

			continue;
		}

		/* number of positive dentries */
		dentry_count++;

		/* store underlying dentry */
		if (dbstart(dentry) == -1)
			set_dbstart(dentry, bindex);
		unionfs_set_lower_dentry_idx(dentry, bindex, hidden_dentry);
		/* FIXME: the following line needs to get fixed to allow
		 * mountpoint crossing
		 */
		unionfs_set_lower_mnt_idx(dentry, bindex,
			mntget(unionfs_lower_mnt_idx(parent_dentry, bindex)));
		set_dbend(dentry, bindex);

		/* update parent directory's atime with the bindex */
		fsstack_copy_attr_atime(parent_dentry->d_inode,
				     hidden_dir_dentry->d_inode);

		/* We terminate file lookups here. */
		if (!S_ISDIR(hidden_dentry->d_inode->i_mode)) {
			if (lookupmode == INTERPOSE_PARTIAL)
				continue;
			if (dentry_count == 1)
				goto out_positive;
			/* This can only happen with mixed D-*-F-* */
			BUG_ON(!S_ISDIR(unionfs_lower_dentry(dentry)->d_inode->i_mode));
			continue;
		}

		opaque = is_opaque_dir(dentry, bindex);
		if (opaque < 0) {
			dput(first_hidden_dentry);
			mntput(first_hidden_mnt);
			err = opaque;
			goto out_free;
		} else if (opaque) {
			set_dbend(dentry, bindex);
			set_dbopaque(dentry, bindex);
			break;
		}
	}

	if (dentry_count)
		goto out_positive;
	else
		goto out_negative;

out_negative:
	if (lookupmode == INTERPOSE_PARTIAL)
		goto out;

	/* If we've only got negative dentries, then use the leftmost one. */
	if (lookupmode == INTERPOSE_REVAL) {
		if (dentry->d_inode)
			UNIONFS_I(dentry->d_inode)->stale = 1;

		goto out;
	}
	/* This should only happen if we found a whiteout. */
	if (first_dentry_offset == -1) {
		nd->dentry = dentry;
		/* FIXME: fix following line for mount point crossing */
		nd->mnt = unionfs_lower_mnt_idx(parent_dentry, bindex);

		first_hidden_dentry = lookup_one_len_nd(name, hidden_dir_dentry,
						     namelen, nd);
		first_dentry_offset = bindex;
		if (IS_ERR(first_hidden_dentry)) {
			err = PTR_ERR(first_hidden_dentry);
			goto out;
		}
		
		/* FIXME: the following line needs to be changed to allow
		 * mountpoint crossing
		 */
		first_hidden_mnt = mntget(unionfs_lower_mnt_idx(dentry, bindex));
	}
	unionfs_set_lower_dentry_idx(dentry, first_dentry_offset, first_hidden_dentry);
	unionfs_set_lower_mnt_idx(dentry, first_dentry_offset, first_hidden_mnt);
	set_dbstart(dentry, first_dentry_offset);
	set_dbend(dentry, first_dentry_offset);

	if (lookupmode == INTERPOSE_REVAL_NEG)
		BUG_ON(dentry->d_inode != NULL);
	else
		d_add(dentry, NULL);
	goto out;

/* This part of the code is for positive dentries. */
out_positive:
	BUG_ON(dentry_count <= 0);

	/* If we're holding onto the first negative dentry & corresponding
	 * vfsmount - throw it out.
	 */
	dput(first_hidden_dentry);
	mntput(first_hidden_mnt);

	/* Partial lookups need to reinterpose, or throw away older negs. */
	if (lookupmode == INTERPOSE_PARTIAL) {
		if (dentry->d_inode) {
			unionfs_reinterpose(dentry);
			goto out;
		}

		/* This somehow turned positive, so it is as if we had a
		 * negative revalidation.
		 */
		lookupmode = INTERPOSE_REVAL_NEG;

		update_bstart(dentry);
		bstart = dbstart(dentry);
		bend = dbend(dentry);
	}

	err = unionfs_interpose(dentry, dentry->d_sb, lookupmode);
	if (err)
		goto out_drop;

	goto out;

out_drop:
	d_drop(dentry);

out_free:
	/* should dput all the underlying dentries on error condition */
	bstart = dbstart(dentry);
	if (bstart >= 0) {
		bend = dbend(dentry);
		for (bindex = bstart; bindex <= bend; bindex++) {
			dput(unionfs_lower_dentry_idx(dentry, bindex));
			mntput(unionfs_lower_mnt_idx(dentry, bindex));
		}
	}
	kfree(UNIONFS_D(dentry)->lower_paths);
	UNIONFS_D(dentry)->lower_paths = NULL;
	set_dbstart(dentry, -1);
	set_dbend(dentry, -1);

out:
	if (!err && UNIONFS_D(dentry)) {
		BUG_ON(dbend(dentry) > UNIONFS_D(dentry)->bcount);
		BUG_ON(dbend(dentry) > sbmax(dentry->d_sb));
		BUG_ON(dbstart(dentry) < 0);
	}
	kfree(whname);
	if (locked_parent)
		unionfs_unlock_dentry(parent_dentry);
	dput(parent_dentry);
	if (locked_child)
		unionfs_unlock_dentry(dentry);
	return ERR_PTR(err);
}
Example #9
0
/*
 * our custom d_alloc_root work-alike
 *
 * we can't use d_alloc_root if we want to use our own interpose function
 * unchanged, so we simply call our own "fake" d_alloc_root
 */
static struct dentry *unionfs_d_alloc_root(struct super_block *sb)
{
    struct dentry *ret = NULL;

    if (sb) {
        static const struct qstr name = {
            .name = "/",
            .len = 1
        };

        ret = d_alloc(NULL, &name);
        if (likely(ret)) {
            ret->d_op = &unionfs_dops;
            ret->d_sb = sb;
            ret->d_parent = ret;
        }
    }
    return ret;
}

/*
 * There is no need to lock the unionfs_super_info's rwsem as there is no
 * way anyone can have a reference to the superblock at this point in time.
 */
static int unionfs_read_super(struct super_block *sb, void *raw_data,
                              int silent)
{
    int err = 0;
    struct unionfs_dentry_info *lower_root_info = NULL;
    int bindex, bstart, bend;

    if (!raw_data) {
        printk(KERN_ERR
               "unionfs: read_super: missing data argument\n");
        err = -EINVAL;
        goto out;
    }

    /* Allocate superblock private data */
    sb->s_fs_info = kzalloc(sizeof(struct unionfs_sb_info), GFP_KERNEL);
    if (unlikely(!UNIONFS_SB(sb))) {
        printk(KERN_CRIT "unionfs: read_super: out of memory\n");
        err = -ENOMEM;
        goto out;
    }

    UNIONFS_SB(sb)->bend = -1;
    atomic_set(&UNIONFS_SB(sb)->generation, 1);
    init_rwsem(&UNIONFS_SB(sb)->rwsem);
    UNIONFS_SB(sb)->high_branch_id = -1; /* -1 == invalid branch ID */

    lower_root_info = unionfs_parse_options(sb, raw_data);
    if (IS_ERR(lower_root_info)) {
        printk(KERN_ERR
               "unionfs: read_super: error while parsing options "
               "(err = %ld)\n", PTR_ERR(lower_root_info));
        err = PTR_ERR(lower_root_info);
        lower_root_info = NULL;
        goto out_free;
    }
    if (lower_root_info->bstart == -1) {
        err = -ENOENT;
        goto out_free;
    }

    /* set the lower superblock field of upper superblock */
    bstart = lower_root_info->bstart;
    BUG_ON(bstart != 0);
    sbend(sb) = bend = lower_root_info->bend;
    for (bindex = bstart; bindex <= bend; bindex++) {
        struct dentry *d = lower_root_info->lower_paths[bindex].dentry;
        atomic_inc(&d->d_sb->s_active);
        unionfs_set_lower_super_idx(sb, bindex, d->d_sb);
    }

    /* max Bytes is the maximum bytes from highest priority branch */
    sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes;

    /*
     * Our c/m/atime granularity is 1 ns because we may stack on file
     * systems whose granularity is as good.  This is important for our
     * time-based cache coherency.
     */
    sb->s_time_gran = 1;

    sb->s_op = &unionfs_sops;

    /* See comment next to the definition of unionfs_d_alloc_root */
    sb->s_root = unionfs_d_alloc_root(sb);
    if (unlikely(!sb->s_root)) {
        err = -ENOMEM;
        goto out_dput;
    }

    /* link the upper and lower dentries */
    sb->s_root->d_fsdata = NULL;
    err = new_dentry_private_data(sb->s_root, UNIONFS_DMUTEX_ROOT);
    if (unlikely(err))
        goto out_freedpd;

    /* Set the lower dentries for s_root */
    for (bindex = bstart; bindex <= bend; bindex++) {
        struct dentry *d;
        struct vfsmount *m;

        d = lower_root_info->lower_paths[bindex].dentry;
        m = lower_root_info->lower_paths[bindex].mnt;

        unionfs_set_lower_dentry_idx(sb->s_root, bindex, d);
        unionfs_set_lower_mnt_idx(sb->s_root, bindex, m);
    }
    dbstart(sb->s_root) = bstart;
    dbend(sb->s_root) = bend;

    /* Set the generation number to one, since this is for the mount. */
    atomic_set(&UNIONFS_D(sb->s_root)->generation, 1);

    /*
     * Call interpose to create the upper level inode.  Only
     * INTERPOSE_LOOKUP can return a value other than 0 on err.
     */
    err = PTR_ERR(unionfs_interpose(sb->s_root, sb, 0));
    unionfs_unlock_dentry(sb->s_root);
    if (!err)
        goto out;
    /* else fall through */

out_freedpd:
    if (UNIONFS_D(sb->s_root)) {
        kfree(UNIONFS_D(sb->s_root)->lower_paths);
        free_dentry_private_data(sb->s_root);
    }
    dput(sb->s_root);

out_dput:
    if (lower_root_info && !IS_ERR(lower_root_info)) {
        for (bindex = lower_root_info->bstart;
                bindex <= lower_root_info->bend; bindex++) {
            struct dentry *d;
            struct vfsmount *m;

            d = lower_root_info->lower_paths[bindex].dentry;
            m = lower_root_info->lower_paths[bindex].mnt;

            dput(d);
            /* initializing: can't use unionfs_mntput here */
            mntput(m);
            /* drop refs we took earlier */
            atomic_dec(&d->d_sb->s_active);
        }
        kfree(lower_root_info->lower_paths);
        kfree(lower_root_info);
        lower_root_info = NULL;
    }

out_free:
    kfree(UNIONFS_SB(sb)->data);
    kfree(UNIONFS_SB(sb));
    sb->s_fs_info = NULL;

out:
    if (lower_root_info && !IS_ERR(lower_root_info)) {
        kfree(lower_root_info->lower_paths);
        kfree(lower_root_info);
    }
    return err;
}
Example #10
0
/*
 * There is no need to lock the wrapfs_super_info's rwsem as there is no
 * way anyone can have a reference to the superblock at this point in time.
 */
static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent)
{
	int err = 0, i = 0;
	struct wrapfs_dentry_info *lower_root_info = NULL;
	struct inode *inode = NULL;
	if (!raw_data) {
		printk(KERN_ERR
			"u2fs: read_super: missing data argument\n");
		err = -EINVAL;
		goto out;
	}

	/* allocate superblock private data */

	sb->s_fs_info = kzalloc(sizeof(struct wrapfs_sb_info), GFP_KERNEL);
	if (!WRAPFS_SB(sb)) {
		printk(KERN_CRIT "u2fs: read_super: out of memory\n");
		err = -ENOMEM;
		goto out_free;
	}

	atomic_set(&WRAPFS_SB(sb)->generation, 1);
	WRAPFS_SB(sb)->high_branch_id = -1;
/*      Parsing the Inputs      */
	lower_root_info = wrapfs_parse_options(sb, raw_data);
	if (IS_ERR(lower_root_info)) {
		printk(KERN_ERR
			"u2fs: read_super: error while parsing options"
			"(err = %ld)\n", PTR_ERR(lower_root_info));

		err = PTR_ERR(lower_root_info);
		lower_root_info = NULL;
		goto out_free;
	}

	/* set the lower superblock field of upper superblock */
	for (i = 0; i <= 1; i++) {
		struct dentry *d = lower_root_info->lower_paths[i].dentry;
		atomic_inc(&d->d_sb->s_active);
		wrapfs_set_lower_super_idx(sb, i, d->d_sb);
	}

	/* inherit maxbytes from highest priority branch */
	sb->s_maxbytes = wrapfs_lower_super_idx(sb, 0)->s_maxbytes;

	/*
	* Our c/m/atime granularity is 1 ns because we may stack on file
	* systems whose granularity is as good.
	*/
	sb->s_time_gran = 1;
	sb->s_op = &wrapfs_sops;

	/* get a new inode and allocate our root dentry */

	inode = wrapfs_new_iget(sb, iunique(sb, 1));
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_sput;
	}

	sb->s_root = d_alloc_root(inode);
	if (unlikely(!sb->s_root)) {
		err = -ENOMEM;
		goto out_iput;
	}

	d_set_d_op(sb->s_root, &wrapfs_dops);

	/* link the upper and lower dentries */
	sb->s_root->d_fsdata = NULL;
	err = new_dentry_private_data(sb->s_root);
	if (unlikely(err))
		goto out_freeroot;

	/* if get here: cannot have error */
	/* set the lower dentries for s_root */

	for (i = 0; i <= 1 ; i++) {
		struct dentry *d;
		struct vfsmount *m;
		d = lower_root_info->lower_paths[i].dentry;
		m = lower_root_info->lower_paths[i].mnt;
		wrapfs_set_lower_dentry_idx(sb->s_root, i, d);
		wrapfs_set_lower_mnt_idx(sb->s_root, i, m);
	}
	atomic_set(&WRAPFS_D(sb->s_root)->generation, 1);
	if (atomic_read(&inode->i_count) <= 1)
		wrapfs_fill_inode(sb->s_root, inode);
	/*
	* No need to call interpose because we already have a positive
	* dentry, which was instantiated by d_alloc_root.  Just need to
	* d_rehash it.
	*/
	d_rehash(sb->s_root);
	if (!silent)
		printk(KERN_INFO
			"u2fs: mounted on top of type\n");
	goto out;

	/* all is well */
	/* no longer needed: free_dentry_private_data(sb->s_root); */
out_freeroot:
	if (WRAPFS_D(sb->s_root)) {
		kfree(WRAPFS_D(sb->s_root)->lower_paths);
		free_dentry_private_data(sb->s_root);
	}
	dput(sb->s_root);
out_iput:
	iput(inode);
out_sput:
	/* drop refs we took earlier */
	if (lower_root_info && !IS_ERR(lower_root_info)) {
		for (i = 0; i <= 1; i++) {
			struct dentry *d;
			d = lower_root_info->lower_paths[i].dentry;
			atomic_dec(&d->d_sb->s_active);
			path_put(&lower_root_info->lower_paths[i]);
		}
		kfree(lower_root_info->lower_paths);
		kfree(lower_root_info);
		lower_root_info = NULL;
	}
out_free:
	kfree(WRAPFS_SB(sb)->data);
	kfree(WRAPFS_SB(sb));
	sb->s_fs_info = NULL;
out:
	if (lower_root_info && !IS_ERR(lower_root_info)) {
		kfree(lower_root_info->lower_paths);
		kfree(lower_root_info);
	}
	return err;
}
Example #11
0
struct dentry *unionfs_lookup_backend(struct dentry *dentry, int lookupmode)
{
	int err = 0;
	struct dentry *hidden_dentry = NULL;
	struct dentry *wh_hidden_dentry = NULL;
	struct dentry *hidden_dir_dentry = NULL;
	struct dentry *parent_dentry = NULL;
	int bindex, bstart, bend, bopaque;
	int dentry_count = 0;	/* Number of positive dentries. */
	int first_dentry_offset = -1;
	struct dentry *first_hidden_dentry = NULL;
	int locked_parent = 0;
	int locked_child = 0;

	int opaque;
	char *whname = NULL;
	const char *name;
	int namelen;

	print_entry("mode = %d", lookupmode);

	/* We should already have a lock on this dentry in the case of a
	 * partial lookup, or a revalidation. Otherwise it is returned from
	 * new_dentry_private_data already locked.  */
	if (lookupmode == INTERPOSE_PARTIAL || lookupmode == INTERPOSE_REVAL
	    || lookupmode == INTERPOSE_REVAL_NEG) {
		verify_locked(dentry);
	} else {
		BUG_ON(dtopd_nocheck(dentry) != NULL);
		locked_child = 1;
	}
	if (lookupmode != INTERPOSE_PARTIAL)
		if ((err = new_dentry_private_data(dentry)))
			goto out;
	/* must initialize dentry operations */
	dentry->d_op = &unionfs_dops;

	parent_dentry = GET_PARENT(dentry);
	/* We never partial lookup the root directory. */
	if (parent_dentry != dentry) {
		lock_dentry(parent_dentry);
		locked_parent = 1;
	} else {
		DPUT(parent_dentry);
		parent_dentry = NULL;
		goto out;
	}

	fist_print_dentry("IN unionfs_lookup (parent)", parent_dentry);
	fist_print_dentry("IN unionfs_lookup (child)", dentry);

	name = dentry->d_name.name;
	namelen = dentry->d_name.len;

	/* No dentries should get created for possible whiteout names. */
	if (!is_validname(name)) {
		err = -EPERM;
		goto out_free;
	}

	/* Now start the actual lookup procedure. */
	bstart = dbstart(parent_dentry);
	bend = dbend(parent_dentry);
	bopaque = dbopaque(parent_dentry);
	BUG_ON(bstart < 0);

	/* It would be ideal if we could convert partial lookups to only have
	 * to do this work when they really need to.  It could probably improve
	 * performance quite a bit, and maybe simplify the rest of the code. */
	if (lookupmode == INTERPOSE_PARTIAL) {
		bstart++;
		if ((bopaque != -1) && (bopaque < bend))
			bend = bopaque;
	}

	fist_dprint(8, "bstart = %d, bend = %d\n", bstart, bend);
	for (bindex = bstart; bindex <= bend; bindex++) {
		hidden_dentry = dtohd_index(dentry, bindex);
		if (lookupmode == INTERPOSE_PARTIAL && hidden_dentry)
			continue;
		BUG_ON(hidden_dentry != NULL);

		hidden_dir_dentry = dtohd_index(parent_dentry, bindex);

		/* if the parent hidden dentry does not exist skip this */
		if (!(hidden_dir_dentry && hidden_dir_dentry->d_inode))
			continue;

		/* also skip it if the parent isn't a directory. */
		if (!S_ISDIR(hidden_dir_dentry->d_inode->i_mode))
			continue;

		/* Reuse the whiteout name because its value doesn't change. */
		if (!whname) {
			whname = alloc_whname(name, namelen);
			if (IS_ERR(whname)) {
				err = PTR_ERR(whname);
				goto out_free;
			}
		}

		/* check if whiteout exists in this branch: lookup .wh.foo */
		wh_hidden_dentry = LOOKUP_ONE_LEN(whname, hidden_dir_dentry,
						  namelen + WHLEN);
		if (IS_ERR(wh_hidden_dentry)) {
			DPUT(first_hidden_dentry);
			err = PTR_ERR(wh_hidden_dentry);
			goto out_free;
		}

		if (wh_hidden_dentry->d_inode) {
			/* We found a whiteout so lets give up. */
			fist_dprint(8, "whiteout found in %d\n", bindex);
			if (S_ISREG(wh_hidden_dentry->d_inode->i_mode)) {
				set_dbend(dentry, bindex);
				set_dbopaque(dentry, bindex);
				DPUT(wh_hidden_dentry);
				break;
			}
			err = -EIO;
			printk(KERN_NOTICE "EIO: Invalid whiteout entry type"
			       " %d.\n", wh_hidden_dentry->d_inode->i_mode);
			DPUT(wh_hidden_dentry);
			DPUT(first_hidden_dentry);
			goto out_free;
		}

		DPUT(wh_hidden_dentry);
		wh_hidden_dentry = NULL;

		/* Now do regular lookup; lookup foo */
		hidden_dentry = LOOKUP_ONE_LEN(name, hidden_dir_dentry,
					       namelen);
		fist_print_generic_dentry("hidden result", hidden_dentry);
		if (IS_ERR(hidden_dentry)) {
			DPUT(first_hidden_dentry);
			err = PTR_ERR(hidden_dentry);
			goto out_free;
		}

		/* Store the first negative dentry specially, because if they
		 * are all negative we need this for future creates. */
		if (!hidden_dentry->d_inode) {
			if (!first_hidden_dentry && (dbstart(dentry) == -1)) {
				first_hidden_dentry = hidden_dentry;
				first_dentry_offset = bindex;
			} else {
				DPUT(hidden_dentry);
			}
			continue;
		}

		/* number of positive dentries */
		dentry_count++;

		/* store underlying dentry */
		if (dbstart(dentry) == -1)
			set_dbstart(dentry, bindex);
		set_dtohd_index(dentry, bindex, hidden_dentry);
		set_dbend(dentry, bindex);

		/* update parent directory's atime with the bindex */
		fist_copy_attr_atime(parent_dentry->d_inode,
				     hidden_dir_dentry->d_inode);

		/* We terminate file lookups here. */
		if (!S_ISDIR(hidden_dentry->d_inode->i_mode)) {
			if (lookupmode == INTERPOSE_PARTIAL)
				continue;
			if (dentry_count == 1)
				goto out_positive;
			/* This can only happen with mixed D-*-F-* */
			BUG_ON(!S_ISDIR(dtohd(dentry)->d_inode->i_mode));
			continue;
		}

		opaque = is_opaque_dir(dentry, bindex);
		if (opaque < 0) {
			DPUT(first_hidden_dentry);
			err = opaque;
			goto out_free;
		}
		if (opaque) {
			set_dbend(dentry, bindex);
			set_dbopaque(dentry, bindex);
			break;
		}
	}

	if (dentry_count)
		goto out_positive;
	else
		goto out_negative;

      out_negative:
	if (lookupmode == INTERPOSE_PARTIAL)
		goto out;

	/* If we've only got negative dentries, then use the leftmost one. */
	if (lookupmode == INTERPOSE_REVAL) {
		if (dentry->d_inode) {
			itopd(dentry->d_inode)->uii_stale = 1;
		}
		goto out;
	}
	/* This should only happen if we found a whiteout. */
	if (first_dentry_offset == -1) {
		first_hidden_dentry = LOOKUP_ONE_LEN(name, hidden_dir_dentry,
						     namelen);
		first_dentry_offset = bindex;
		if (IS_ERR(first_hidden_dentry)) {
			err = PTR_ERR(first_hidden_dentry);
			goto out;
		}
	}
	set_dtohd_index(dentry, first_dentry_offset, first_hidden_dentry);
	set_dbstart(dentry, first_dentry_offset);
	set_dbend(dentry, first_dentry_offset);

	if (lookupmode == INTERPOSE_REVAL_NEG)
		BUG_ON(dentry->d_inode != NULL);
	else
		d_add(dentry, NULL);
	goto out;

/* This part of the code is for positive dentries. */
      out_positive:
	BUG_ON(dentry_count <= 0);

	/* If we're holding onto the first negative dentry throw it out. */
	DPUT(first_hidden_dentry);

	/* Partial lookups need to reinterpose, or throw away older negs. */
	if (lookupmode == INTERPOSE_PARTIAL) {
		if (dentry->d_inode) {
			unionfs_reinterpose(dentry);
			goto out;
		}

		/* This somehow turned positive, so it is as if we had a
		 * negative revalidation.  */
		lookupmode = INTERPOSE_REVAL_NEG;

		update_bstart(dentry);
		bstart = dbstart(dentry);
		bend = dbend(dentry);
	}

	err = unionfs_interpose(dentry, dentry->d_sb, lookupmode);
	if (err)
		goto out_drop;

	fist_checkinode(dentry->d_inode, "unionfs_lookup OUT: child");
	fist_checkinode(parent_dentry->d_inode, "unionfs_lookup OUT: dir");
	goto out;

      out_drop:
	d_drop(dentry);

      out_free:
	/* should dput all the underlying dentries on error condition */
	bstart = dbstart(dentry);
	if (bstart >= 0) {
		bend = dbend(dentry);
		for (bindex = bstart; bindex <= bend; bindex++)
			DPUT(dtohd_index(dentry, bindex));
	}
	KFREE(dtohd_ptr(dentry));
	dtohd_ptr(dentry) = NULL;
	set_dbstart(dentry, -1);
	set_dbend(dentry, -1);

      out:
	if (!err && dtopd(dentry)) {
		BUG_ON(dbend(dentry) > dtopd(dentry)->udi_bcount);
		BUG_ON(dbend(dentry) > sbmax(dentry->d_sb));
		BUG_ON(dbstart(dentry) < 0);
	}
	KFREE(whname);
	fist_print_dentry("OUT unionfs_lookup (parent)", parent_dentry);
	fist_print_dentry("OUT unionfs_lookup (child)", dentry);
	if (locked_parent)
		unlock_dentry(parent_dentry);
	DPUT(parent_dentry);
	if (locked_child)
		unlock_dentry(dentry);
	print_exit_status(err);
	return ERR_PTR(err);
}
/*
 * our custom d_alloc_root work-alike
 *
 * we can't use d_alloc_root if we want to use our own interpose function
 * unchanged, so we simply call our own "fake" d_alloc_root
 */
static struct dentry *sdcardfs_d_alloc_root(struct super_block *sb)
{
	struct dentry *ret = NULL;

	if (sb) {
		static const struct qstr name = {
			.name = "/",
			.len = 1
		};

		ret = d_alloc(NULL, &name);
		if (ret) {
			d_set_d_op(ret, &sdcardfs_dops);
			ret->d_sb = sb;
			ret->d_parent = ret;
		}
	}
	return ret;
}

/*
 * There is no need to lock the sdcardfs_super_info's rwsem as there is no
 * way anyone can have a reference to the superblock at this point in time.
 */
static int sdcardfs_read_super(struct super_block *sb, const char *dev_name, 
						void *raw_data, int silent)
{
	int err = 0;
	int debug;
	struct super_block *lower_sb;
	struct path lower_path;
	struct sdcardfs_sb_info *sb_info;

	if (!dev_name) {
		printk(KERN_ERR
		       "sdcardfs: read_super: missing dev_name argument\n");
		err = -EINVAL;
		goto out;
	}

	printk(KERN_INFO "sdcardfs: dev_name -> %s\n", dev_name);
	printk(KERN_INFO "sdcardfs: options -> %s\n", (char *)raw_data);

	/* parse lower path */
	err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
			&lower_path);
	if (err) {
		printk(KERN_ERR	"sdcardfs: error accessing "
		       "lower directory '%s'\n", dev_name);
		goto out;
	}

	/* allocate superblock private data */
	sb->s_fs_info = kzalloc(sizeof(struct sdcardfs_sb_info), GFP_KERNEL);
	if (!SDCARDFS_SB(sb)) {
		printk(KERN_CRIT "sdcardfs: read_super: out of memory\n");
		err = -ENOMEM;
		goto out_free;
	}

	/* setup fs_uid and fs_gid for FAT emulation : wjlee */
	sb_info = sb->s_fs_info;
	sb_info->fs_uid = AID_ROOT;
	sb_info->fs_gid = AID_SDCARD_RW;

	/* parse options */
	err = parse_options(sb, raw_data, silent, &debug, &sb_info->options);
	if (err) {
		printk(KERN_ERR	"sdcardfs: invalid options\n");
		goto out_freesbi;
	}


	/* set the lower superblock field of upper superblock */
	lower_sb = lower_path.dentry->d_sb;
	atomic_inc(&lower_sb->s_active);
	sdcardfs_set_lower_super(sb, lower_sb);

	/* inherit maxbytes from lower file system */
	sb->s_maxbytes = lower_sb->s_maxbytes;

	/*
	 * Our c/m/atime granularity is 1 ns because we may stack on file
	 * systems whose granularity is as good.
	 */
	sb->s_time_gran = 1;

	sb->s_op = &sdcardfs_sops;

	/* see comment next to the definition of sdcardfs_d_alloc_root */
	sb->s_root = sdcardfs_d_alloc_root(sb);
	if (!sb->s_root) {
		err = -ENOMEM;
		goto out_sput;
	}

	/* link the upper and lower dentries */
	sb->s_root->d_fsdata = NULL;
	err = new_dentry_private_data(sb->s_root);
	if (err)
		goto out_freeroot;

	/* set the lower dentries for s_root */
	sdcardfs_set_lower_path(sb->s_root, &lower_path);

	/* call interpose to create the upper level inode */
	err = sdcardfs_interpose(sb->s_root, sb, &lower_path);
	if (!err) {
		if (!silent)
			printk(KERN_INFO
			       "sdcardfs: mounted on top of %s type %s\n",
			       dev_name, lower_sb->s_type->name);
		goto out;
	}
	/* else error: fall through */

	free_dentry_private_data(sb->s_root);
out_freeroot:
	dput(sb->s_root);
out_sput:
	/* drop refs we took earlier */
	atomic_dec(&lower_sb->s_active);
out_freesbi:
	kfree(SDCARDFS_SB(sb));
	sb->s_fs_info = NULL;
out_free:
	path_put(&lower_path);

out:
	return err;
}
Example #13
0
/*
 * There is no need to lock the unionfs_super_info's rwsem as there is no
 * way anyone can have a reference to the superblock at this point in time.
 */
static int unionfs_read_super(struct super_block *sb, void *raw_data,
			      int silent)
{
	int err = 0;
	struct unionfs_dentry_info *lower_root_info = NULL;
	int bindex, bstart, bend;
	struct inode *inode = NULL;

	if (!raw_data) {
		printk(KERN_ERR
		       "unionfs: read_super: missing data argument\n");
		err = -EINVAL;
		goto out;
	}

	/* Allocate superblock private data */
	sb->s_fs_info = kzalloc(sizeof(struct unionfs_sb_info), GFP_KERNEL);
	if (unlikely(!UNIONFS_SB(sb))) {
		printk(KERN_CRIT "unionfs: read_super: out of memory\n");
		err = -ENOMEM;
		goto out;
	}

	UNIONFS_SB(sb)->bend = -1;
	atomic_set(&UNIONFS_SB(sb)->generation, 1);
	init_rwsem(&UNIONFS_SB(sb)->rwsem);
	UNIONFS_SB(sb)->high_branch_id = -1; /* -1 == invalid branch ID */

	lower_root_info = unionfs_parse_options(sb, raw_data);
	if (IS_ERR(lower_root_info)) {
		printk(KERN_ERR
		       "unionfs: read_super: error while parsing options "
		       "(err = %ld)\n", PTR_ERR(lower_root_info));
		err = PTR_ERR(lower_root_info);
		lower_root_info = NULL;
		goto out_free;
	}
	if (lower_root_info->bstart == -1) {
		err = -ENOENT;
		goto out_free;
	}

	/* set the lower superblock field of upper superblock */
	bstart = lower_root_info->bstart;
	BUG_ON(bstart != 0);
	sbend(sb) = bend = lower_root_info->bend;
	for (bindex = bstart; bindex <= bend; bindex++) {
		struct dentry *d = lower_root_info->lower_paths[bindex].dentry;
		atomic_inc(&d->d_sb->s_active);
		unionfs_set_lower_super_idx(sb, bindex, d->d_sb);
	}

	/* max Bytes is the maximum bytes from highest priority branch */
	sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes;

	/*
	 * Our c/m/atime granularity is 1 ns because we may stack on file
	 * systems whose granularity is as good.  This is important for our
	 * time-based cache coherency.
	 */
	sb->s_time_gran = 1;

	sb->s_op = &unionfs_sops;

	/* get a new inode and allocate our root dentry */
	inode = unionfs_iget(sb, iunique(sb, UNIONFS_ROOT_INO));
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_dput;
	}
	sb->s_root = d_make_root(inode);
	if (unlikely(!sb->s_root)) {
		err = -ENOMEM;
		goto out_iput;
	}
	d_set_d_op(sb->s_root, &unionfs_dops);

	/* link the upper and lower dentries */
	sb->s_root->d_fsdata = NULL;
	err = new_dentry_private_data(sb->s_root, UNIONFS_DMUTEX_ROOT);
	if (unlikely(err))
		goto out_freedpd;

	/* if get here: cannot have error */

	/* Set the lower dentries for s_root */
	for (bindex = bstart; bindex <= bend; bindex++) {
		struct dentry *d;
		struct vfsmount *m;

		d = lower_root_info->lower_paths[bindex].dentry;
		m = lower_root_info->lower_paths[bindex].mnt;

		unionfs_set_lower_dentry_idx(sb->s_root, bindex, d);
		unionfs_set_lower_mnt_idx(sb->s_root, bindex, m);
	}
	dbstart(sb->s_root) = bstart;
	dbend(sb->s_root) = bend;

	/* Set the generation number to one, since this is for the mount. */
	atomic_set(&UNIONFS_D(sb->s_root)->generation, 1);

	if (atomic_read(&inode->i_count) <= 1)
		unionfs_fill_inode(sb->s_root, inode);

	/*
	 * No need to call interpose because we already have a positive
	 * dentry, which was instantiated by d_alloc_root.  Just need to
	 * d_rehash it.
	 */
	d_rehash(sb->s_root);

	unionfs_unlock_dentry(sb->s_root);
	goto out; /* all is well */

out_freedpd:
	if (UNIONFS_D(sb->s_root)) {
		kfree(UNIONFS_D(sb->s_root)->lower_paths);
		free_dentry_private_data(sb->s_root);
	}
	dput(sb->s_root);

out_iput:
	iput(inode);

out_dput:
	if (lower_root_info && !IS_ERR(lower_root_info)) {
		for (bindex = lower_root_info->bstart;
		     bindex <= lower_root_info->bend; bindex++) {
			struct dentry *d;
			d = lower_root_info->lower_paths[bindex].dentry;
			/* drop refs we took earlier */
			atomic_dec(&d->d_sb->s_active);
			path_put(&lower_root_info->lower_paths[bindex]);
		}
		kfree(lower_root_info->lower_paths);
		kfree(lower_root_info);
		lower_root_info = NULL;
	}

out_free:
	kfree(UNIONFS_SB(sb)->data);
	kfree(UNIONFS_SB(sb));
	sb->s_fs_info = NULL;

out:
	if (lower_root_info && !IS_ERR(lower_root_info)) {
		kfree(lower_root_info->lower_paths);
		kfree(lower_root_info);
	}
	return err;
}
Example #14
0
/*
 * There is no need to lock the esdfs_super_info's rwsem as there is no
 * way anyone can have a reference to the superblock at this point in time.
 */
static int esdfs_read_super(struct super_block *sb, const char *dev_name,
		void *raw_data, int silent)
{
	int err = 0;
	struct super_block *lower_sb;
	struct path lower_path;
	struct esdfs_sb_info *sbi;
	struct inode *inode;

	if (!dev_name) {
		esdfs_msg(sb, KERN_ERR, "missing dev_name argument\n");
		err = -EINVAL;
		goto out;
	}

	/* parse lower path */
	err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
			&lower_path);
	if (err) {
		esdfs_msg(sb, KERN_ERR, "error accessing lower directory '%s'\n",
			dev_name);
		goto out;
	}

	/* allocate superblock private data */
	sb->s_fs_info = kzalloc(sizeof(struct esdfs_sb_info), GFP_KERNEL);
	sbi = ESDFS_SB(sb);
	if (!sbi) {
		esdfs_msg(sb, KERN_CRIT, "read_super: out of memory\n");
		err = -ENOMEM;
		goto out_pput;
	}

	/* set defaults and then parse the mount options */
	memcpy(&sbi->lower_perms,
	       &esdfs_perms_table[ESDFS_PERMS_LOWER_DEFAULT],
	       sizeof(struct esdfs_perms));
	memcpy(&sbi->upper_perms,
	       &esdfs_perms_table[ESDFS_PERMS_UPPER_LEGACY],
	       sizeof(struct esdfs_perms));
	err = parse_options(sb, (char *)raw_data);
	if (err)
		goto out_free;

	/* set the lower superblock field of upper superblock */
	lower_sb = lower_path.dentry->d_sb;
	atomic_inc(&lower_sb->s_active);
	esdfs_set_lower_super(sb, lower_sb);

	/* inherit maxbytes from lower file system */
	sb->s_maxbytes = lower_sb->s_maxbytes;

	/*
	 * Our c/m/atime granularity is 1 ns because we may stack on file
	 * systems whose granularity is as good.
	 */
	sb->s_time_gran = 1;

	sb->s_op = &esdfs_sops;

	/* get a new inode and allocate our root dentry */
	inode = esdfs_iget(sb, lower_path.dentry->d_inode);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_sput;
	}
	sb->s_root = d_make_root(inode);
	if (!sb->s_root) {
		err = -ENOMEM;
		goto out_iput;
	}
	d_set_d_op(sb->s_root, &esdfs_dops);

	/* link the upper and lower dentries */
	sb->s_root->d_fsdata = NULL;
	err = new_dentry_private_data(sb->s_root);
	if (err)
		goto out_freeroot;

	/* if get here: cannot have error */

	/* set the lower dentries for s_root */
	esdfs_set_lower_path(sb->s_root, &lower_path);
#ifdef CONFIG_SECURITY_SELINUX
	security_secctx_to_secid(ESDFS_LOWER_SECCTX,
				 strlen(ESDFS_LOWER_SECCTX),
				 &sbi->lower_secid);
#endif
	/*
	 * No need to call interpose because we already have a positive
	 * dentry, which was instantiated by d_make_root.  Just need to
	 * d_rehash it.
	 */
	d_rehash(sb->s_root);
	if (!silent)
		esdfs_msg(sb, KERN_INFO, "mounted on top of %s type %s\n",
			dev_name, lower_sb->s_type->name);

	if (!ESDFS_DERIVE_PERMS(sbi))
		goto out;

	/* let user know that we ignore this option in derived mode */
	if (memcmp(&sbi->upper_perms,
		   &esdfs_perms_table[ESDFS_PERMS_UPPER_LEGACY],
		   sizeof(struct esdfs_perms)))
		esdfs_msg(sb, KERN_WARNING, "'upper' mount option ignored in derived mode\n");

	/* all derived modes start with the same, basic root */
	memcpy(&sbi->upper_perms,
	       &esdfs_perms_table[ESDFS_PERMS_UPPER_DERIVED],
	       sizeof(struct esdfs_perms));

	/*
	 * In Android 3.0 all user conent in the emulated storage tree was
	 * stored in /data/media.  Android 4.2 introduced multi-user support,
	 * which required that the primary user's content be migrated from
	 * /data/media to /data/media/0.  The framework then uses bind mounts
	 * to create per-process namespaces to isolate each user's tree at
	 * /data/media/N.  This approach of having each user in a common root
	 * is now considered "legacy" by the sdcard service.
	 */
	if (test_opt(sbi, DERIVE_LEGACY)) {
		ESDFS_I(inode)->tree = ESDFS_TREE_ROOT_LEGACY;
		sbi->obb_parent = dget(sb->s_root);
	/*
	 * Android 4.4 reorganized this sturcture yet again, so that the
	 * primary user's content was again at the root.  Secondary users'
	 * content is found in Android/user/N.  Emulated internal storage still
	 * seems to use the legacy tree, but secondary external storage uses
	 * this method.
	 */
	} else if (test_opt(sbi, DERIVE_UNIFIED))
		ESDFS_I(inode)->tree = ESDFS_TREE_ROOT;
	/*
	 * Later versions of Android organize user content using quantum
	 * entanglement, which has a low probability of being supported by
	 * this driver.
	 */
	else
		esdfs_msg(sb, KERN_WARNING, "unsupported derived permissions mode\n");

	/* initialize root inode */
	esdfs_derive_perms(sb->s_root);

	goto out;

out_freeroot:
	dput(sb->s_root);
out_iput:
	iput(inode);
out_sput:
	/* drop refs we took earlier */
	atomic_dec(&lower_sb->s_active);
out_free:
	kfree(ESDFS_SB(sb));
	sb->s_fs_info = NULL;
out_pput:
	path_put(&lower_path);

out:
	return err;
}
Example #15
0
/*
 * our custom d_alloc_root work-alike
 *
 * we can't use d_alloc_root if we want to use our own interpose function
 * unchanged, so we simply call our own "fake" d_alloc_root
 */
static struct dentry *sdcardfs_d_alloc_root(struct super_block *sb)
{
	struct dentry *ret = NULL;
	//struct sdcardfs_sb_info *sbi = SDCARDFS_SB(sb);

	struct dentry *(*__d_alloc_new)(struct super_block *, const struct qstr *) = (void *)kallsyms_lookup_name("__d_alloc");

	if (sb) {
		static const struct qstr name = {
			.name = "/",
			.len = 1
		};

		ret = __d_alloc_new(sb, &name);
		if (ret) {
			d_set_d_op(ret, &sdcardfs_ci_dops);
			ret->d_parent = ret;
		}
	}
	return ret;
}

/*
 * There is no need to lock the sdcardfs_super_info's rwsem as there is no
 * way anyone can have a reference to the superblock at this point in time.
 */
static int sdcardfs_read_super(struct super_block *sb, const char *dev_name, 
						void *raw_data, int silent)
{
	int err = 0;
	int debug;
	struct super_block *lower_sb;
	struct path lower_path;
	struct sdcardfs_sb_info *sb_info;
	void *pkgl_id;

	printk(KERN_INFO "sdcardfs version 2.0\n");

	if (!dev_name) {
		printk(KERN_ERR
		       "sdcardfs: read_super: missing dev_name argument\n");
		err = -EINVAL;
		goto out;
	}

	printk(KERN_INFO "sdcardfs: dev_name -> %s\n", dev_name);
	printk(KERN_INFO "sdcardfs: options -> %s\n", (char *)raw_data);

	/* parse lower path */
	err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
			&lower_path);
	if (err) {
		printk(KERN_ERR	"sdcardfs: error accessing "
		       "lower directory '%s'\n", dev_name);
		goto out;
	}

	/* allocate superblock private data */
	sb->s_fs_info = kzalloc(sizeof(struct sdcardfs_sb_info), GFP_KERNEL);
	if (!SDCARDFS_SB(sb)) {
		printk(KERN_CRIT "sdcardfs: read_super: out of memory\n");
		err = -ENOMEM;
		goto out_free;
	}

	sb_info = sb->s_fs_info;

	/* parse options */
	err = parse_options(sb, raw_data, silent, &debug, &sb_info->options);
	if (err) {
		printk(KERN_ERR	"sdcardfs: invalid options\n");
		goto out_freesbi;
	}

	if (sb_info->options.derive != DERIVE_NONE) {
		pkgl_id = packagelist_create(sb_info->options.write_gid);
		if(IS_ERR(pkgl_id))
			goto out_freesbi;
		else
			sb_info->pkgl_id = pkgl_id;
	}

	/* set the lower superblock field of upper superblock */
	lower_sb = lower_path.dentry->d_sb;
	atomic_inc(&lower_sb->s_active);
	sdcardfs_set_lower_super(sb, lower_sb);

	/* inherit maxbytes from lower file system */
	sb->s_maxbytes = lower_sb->s_maxbytes;

	/*
	 * Our c/m/atime granularity is 1 ns because we may stack on file
	 * systems whose granularity is as good.
	 */
	sb->s_time_gran = 1;

	sb->s_magic = SDCARDFS_SUPER_MAGIC;
	sb->s_op = &sdcardfs_sops;

	/* see comment next to the definition of sdcardfs_d_alloc_root */
	sb->s_root = sdcardfs_d_alloc_root(sb);
	if (!sb->s_root) {
		err = -ENOMEM;
		goto out_sput;
	}

	/* link the upper and lower dentries */
	sb->s_root->d_fsdata = NULL;
	err = new_dentry_private_data(sb->s_root);
	if (err)
		goto out_freeroot;

	/* set the lower dentries for s_root */
	sdcardfs_set_lower_path(sb->s_root, &lower_path);

	/* call interpose to create the upper level inode */
	err = sdcardfs_interpose(sb->s_root, sb, &lower_path);
	if (!err) {
		/* setup permission policy */
		switch(sb_info->options.derive) {
			case DERIVE_NONE:
				setup_derived_state(sb->s_root->d_inode, 
					PERM_ROOT, 0, AID_ROOT, AID_SDCARD_RW, 00775);
				sb_info->obbpath_s = NULL;
				break;
			case DERIVE_LEGACY:
				/* Legacy behavior used to support internal multiuser layout which
				 * places user_id at the top directory level, with the actual roots
				 * just below that. Shared OBB path is also at top level. */
				setup_derived_state(sb->s_root->d_inode, 
				        PERM_LEGACY_PRE_ROOT, 0, AID_ROOT, AID_SDCARD_R, 00771);
				/* initialize the obbpath string and lookup the path 
				 * sb_info->obb_path will be deactivated by path_put 
				 * on sdcardfs_put_super */
				sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL);
				snprintf(sb_info->obbpath_s, PATH_MAX, "%s/obb", dev_name);
				err =  prepare_dir(sb_info->obbpath_s, 
							sb_info->options.fs_low_uid,
							sb_info->options.fs_low_gid, 00755);
				if(err)
					printk(KERN_ERR "sdcardfs: %s: %d, error on creating %s\n", 
							__func__,__LINE__, sb_info->obbpath_s);
				break;
			case DERIVE_UNIFIED:
				/* Unified multiuser layout which places secondary user_id under
				 * /Android/user and shared OBB path under /Android/obb. */
				setup_derived_state(sb->s_root->d_inode, 
						PERM_ROOT, 0, AID_ROOT, AID_SDCARD_R, 00771);
				
				sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL);
				snprintf(sb_info->obbpath_s, PATH_MAX, "%s/Android/obb", dev_name);
				break;
		}
		fix_derived_permission(sb->s_root->d_inode);

		if (!silent)
			printk(KERN_INFO "sdcardfs: mounted on top of %s type %s\n",
						dev_name, lower_sb->s_type->name);
		goto out;
	}
	/* else error: fall through */

	free_dentry_private_data(sb->s_root);
out_freeroot:
	dput(sb->s_root);
out_sput:
	/* drop refs we took earlier */
	atomic_dec(&lower_sb->s_active);
	packagelist_destroy(sb_info->pkgl_id);
out_freesbi:
	kfree(SDCARDFS_SB(sb));
	sb->s_fs_info = NULL;
out_free:
	path_put(&lower_path);

out:
	return err;
}
Example #16
0
/*
 * our custom d_alloc_root work-alike
 *
 * we can't use d_alloc_root if we want to use our own interpose function
 * unchanged, so we simply call our own "fake" d_alloc_root
 */
static struct dentry *sdcardfs_d_alloc_root(struct super_block *sb)
{
	struct dentry *ret = NULL;

	if (sb) {
		static const struct qstr name = {
			.name = "/",
			.len = 1
		};

		ret = d_alloc(NULL, &name);
		if (ret) {
			d_set_d_op(ret, &sdcardfs_ci_dops);
			ret->d_sb = sb;
			ret->d_parent = ret;
		}
	}
	return ret;
}
#endif

DEFINE_MUTEX(sdcardfs_super_list_lock);
LIST_HEAD(sdcardfs_super_list);
EXPORT_SYMBOL_GPL(sdcardfs_super_list_lock);
EXPORT_SYMBOL_GPL(sdcardfs_super_list);

/*
 * There is no need to lock the sdcardfs_super_info's rwsem as there is no
 * way anyone can have a reference to the superblock at this point in time.
 */
static int sdcardfs_read_super(struct super_block *sb, const char *dev_name,
						void *raw_data, int silent)
{
	int err = 0;
	int debug;
	struct super_block *lower_sb;
	struct path lower_path;
	struct sdcardfs_sb_info *sb_info;
	struct inode *inode;

	printk(KERN_INFO "sdcardfs version 2.0\n");

	if (!dev_name) {
		printk(KERN_ERR
		       "sdcardfs: read_super: missing dev_name argument\n");
		err = -EINVAL;
		goto out;
	}

	printk(KERN_INFO "sdcardfs: dev_name -> %s\n", dev_name);
	printk(KERN_INFO "sdcardfs: options -> %s\n", (char *)raw_data);

	/* parse lower path */
	err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
			&lower_path);
	if (err) {
		printk(KERN_ERR	"sdcardfs: error accessing lower directory '%s'\n", dev_name);
		goto out;
	}

	/* allocate superblock private data */
	sb->s_fs_info = kzalloc(sizeof(struct sdcardfs_sb_info), GFP_KERNEL);
	if (!SDCARDFS_SB(sb)) {
		printk(KERN_CRIT "sdcardfs: read_super: out of memory\n");
		err = -ENOMEM;
		goto out_free;
	}

	sb_info = sb->s_fs_info;
	/* parse options */
	err = parse_options(sb, raw_data, silent, &debug, &sb_info->options);
	if (err) {
		printk(KERN_ERR	"sdcardfs: invalid options\n");
		goto out_freesbi;
	}

	/* set the lower superblock field of upper superblock */
	lower_sb = lower_path.dentry->d_sb;
	atomic_inc(&lower_sb->s_active);
	sdcardfs_set_lower_super(sb, lower_sb);

	/* inherit maxbytes from lower file system */
	sb->s_maxbytes = lower_sb->s_maxbytes;

	/*
	 * Our c/m/atime granularity is 1 ns because we may stack on file
	 * systems whose granularity is as good.
	 */
	sb->s_time_gran = 1;

	sb->s_magic = SDCARDFS_SUPER_MAGIC;
	sb->s_op = &sdcardfs_sops;

	/* get a new inode and allocate our root dentry */
	inode = sdcardfs_iget(sb, lower_path.dentry->d_inode, 0);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_sput;
	}
	sb->s_root = d_make_root(inode);
 	if (!sb->s_root) {
 		err = -ENOMEM;
		goto out_iput;
 	}
	d_set_d_op(sb->s_root, &sdcardfs_ci_dops);

	/* link the upper and lower dentries */
	sb->s_root->d_fsdata = NULL;
	err = new_dentry_private_data(sb->s_root);
	if (err)
		goto out_freeroot;

	/* set the lower dentries for s_root */
	sdcardfs_set_lower_path(sb->s_root, &lower_path);

	/*
	 * No need to call interpose because we already have a positive
	 * dentry, which was instantiated by d_make_root.  Just need to
	 * d_rehash it.
	 */
	d_rehash(sb->s_root);

	/* setup permission policy */
	sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL);
	mutex_lock(&sdcardfs_super_list_lock);
	if(sb_info->options.multiuser) {
		setup_derived_state(sb->s_root->d_inode, PERM_PRE_ROOT, sb_info->options.fs_user_id, AID_ROOT, false, sb->s_root->d_inode);
		snprintf(sb_info->obbpath_s, PATH_MAX, "%s/obb", dev_name);
		/*err =  prepare_dir(sb_info->obbpath_s,
					sb_info->options.fs_low_uid,
					sb_info->options.fs_low_gid, 00755);*/
	} else {
		setup_derived_state(sb->s_root->d_inode, PERM_ROOT, sb_info->options.fs_user_id, AID_ROOT, false, sb->s_root->d_inode);
		snprintf(sb_info->obbpath_s, PATH_MAX, "%s/Android/obb", dev_name);
	}
	fix_derived_permission(sb->s_root->d_inode);
	sb_info->sb = sb;
	list_add(&sb_info->list, &sdcardfs_super_list);
	mutex_unlock(&sdcardfs_super_list_lock);

	if (!silent)
		printk(KERN_INFO "sdcardfs: mounted on top of %s type %s\n",
				dev_name, lower_sb->s_type->name);
	goto out; /* all is well */

	/* no longer needed: free_dentry_private_data(sb->s_root); */
out_freeroot:
	dput(sb->s_root);
out_iput:
	iput(inode);
out_sput:
	/* drop refs we took earlier */
	atomic_dec(&lower_sb->s_active);
out_freesbi:
	kfree(SDCARDFS_SB(sb));
	sb->s_fs_info = NULL;
out_free:
	path_put(&lower_path);

out:
	return err;
}
Example #17
0
static struct dentry *unionfs_d_alloc_root(struct super_block *sb)
{
	struct dentry *ret = NULL;

	if (sb) {
		static const struct qstr name = {.name = "/",.len = 1 };

		ret = d_alloc(NULL, &name);
		if (ret) {
			ret->d_op = &unionfs_dops;
			ret->d_sb = sb;
			ret->d_parent = ret;
		}
	}
	return ret;
}

static int unionfs_read_super(struct super_block *sb, void *raw_data,
			      int silent)
{
	int err = 0;

	struct unionfs_dentry_info *hidden_root_info = NULL;
	int bindex, bstart, bend;
	unsigned long long maxbytes;

	print_entry_location();

	if (!raw_data) {
		printk(KERN_WARNING
		       "unionfs_read_super: missing data argument\n");
		err = -EINVAL;
		goto out;
	}

	/*
	 * Allocate superblock private data
	 */
	stopd_lhs(sb) = KZALLOC(sizeof(struct unionfs_sb_info), GFP_KERNEL);
	if (!stopd(sb)) {
		printk(KERN_WARNING "%s: out of memory\n", __FUNCTION__);
		err = -ENOMEM;
		goto out;
	}
	stopd(sb)->b_end = -1;
	atomic_set(&stopd(sb)->usi_generation, 1);
	init_rwsem(&stopd(sb)->usi_rwsem);

	hidden_root_info = unionfs_parse_options(sb, raw_data);
	if (IS_ERR(hidden_root_info)) {
		printk(KERN_WARNING
		       "unionfs_read_super: error while parsing options (err = %ld)\n",
		       PTR_ERR(hidden_root_info));
		err = PTR_ERR(hidden_root_info);
		hidden_root_info = NULL;
		goto out_free;
	}
	if (hidden_root_info->udi_bstart == -1) {
		err = -ENOENT;
		goto out_free;
	}

	/* set the hidden superblock field of upper superblock */
	bstart = hidden_root_info->udi_bstart;
	BUG_ON(bstart != 0);
	sbend(sb) = bend = hidden_root_info->udi_bend;
	for (bindex = bstart; bindex <= bend; bindex++) {
		struct dentry *d;

		d = hidden_root_info->udi_dentry[bindex];

		set_stohs_index(sb, bindex, d->d_sb);
	}

	/* Unionfs: Max Bytes is the maximum bytes from among all the branches */
	maxbytes = -1;
	for (bindex = bstart; bindex <= bend; bindex++)
		if (maxbytes < stohs_index(sb, bindex)->s_maxbytes)
			maxbytes = stohs_index(sb, bindex)->s_maxbytes;
	sb->s_maxbytes = maxbytes;

	sb->s_op = &unionfs_sops;
	sb->s_export_op = &unionfs_export_ops;

	/*
	 * we can't use d_alloc_root if we want to use
	 * our own interpose function unchanged,
	 * so we simply call our own "fake" d_alloc_root
	 */
	sb->s_root = unionfs_d_alloc_root(sb);
	if (!sb->s_root) {
		err = -ENOMEM;
		goto out_dput;
	}

	/* link the upper and lower dentries */
	dtopd_lhs(sb->s_root) = NULL;
	if ((err = new_dentry_private_data(sb->s_root)))
		goto out_freedpd;

	/* Set the hidden dentries for s_root */
	for (bindex = bstart; bindex <= bend; bindex++) {
		struct dentry *d;

		d = hidden_root_info->udi_dentry[bindex];

		set_dtohd_index(sb->s_root, bindex, d);
	}
	set_dbstart(sb->s_root, bstart);
	set_dbend(sb->s_root, bend);

	/* Set the generation number to one, since this is for the mount. */
	atomic_set(&dtopd(sb->s_root)->udi_generation, 1);

	/* call interpose to create the upper level inode */
	if ((err = unionfs_interpose(sb->s_root, sb, 0)))
		goto out_freedpd;
	unlock_dentry(sb->s_root);
	goto out;

      out_freedpd:
	if (dtopd(sb->s_root)) {
		KFREE(dtohd_ptr(sb->s_root));
		free_dentry_private_data(dtopd(sb->s_root));
	}
	DPUT(sb->s_root);
      out_dput:
	if (hidden_root_info && !IS_ERR(hidden_root_info)) {
		for (bindex = hidden_root_info->udi_bstart;
		     bindex <= hidden_root_info->udi_bend; bindex++) {
			struct dentry *d;

			d = hidden_root_info->udi_dentry[bindex];

			if (d)
				DPUT(d);

			if (stopd(sb) && stohiddenmnt_index(sb, bindex))
				mntput(stohiddenmnt_index(sb, bindex));
		}
		KFREE(hidden_root_info->udi_dentry);
		KFREE(hidden_root_info);
		hidden_root_info = NULL;
	}
      out_free:
	KFREE(stopd(sb)->usi_data);
	KFREE(stopd(sb));
	stopd_lhs(sb) = NULL;
      out:
	if (hidden_root_info && !IS_ERR(hidden_root_info)) {
		KFREE(hidden_root_info->udi_dentry);
		KFREE(hidden_root_info);
	}
	print_exit_status(err);
	return err;
}